1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16#include <linux/kernel.h>
17#include <linux/init.h>
18#include <linux/timer.h>
19#include <linux/interrupt.h>
20#include <linux/module.h>
21#include <linux/console.h>
22#include <linux/tty.h>
23#include <linux/tty_flip.h>
24#include <linux/serial.h>
25#include <linux/serial_core.h>
26#include <linux/platform_device.h>
27#include <linux/of.h>
28#include <linux/io.h>
29#include <linux/altera_uart.h>
30
31#define DRV_NAME "altera_uart"
32#define SERIAL_ALTERA_MAJOR 204
33#define SERIAL_ALTERA_MINOR 213
34
35
36
37
38
39
40#define ALTERA_UART_SIZE 32
41
42#define ALTERA_UART_RXDATA_REG 0
43#define ALTERA_UART_TXDATA_REG 4
44#define ALTERA_UART_STATUS_REG 8
45#define ALTERA_UART_CONTROL_REG 12
46#define ALTERA_UART_DIVISOR_REG 16
47#define ALTERA_UART_EOP_REG 20
48
49#define ALTERA_UART_STATUS_PE_MSK 0x0001
50#define ALTERA_UART_STATUS_FE_MSK 0x0002
51#define ALTERA_UART_STATUS_BRK_MSK 0x0004
52#define ALTERA_UART_STATUS_ROE_MSK 0x0008
53#define ALTERA_UART_STATUS_TOE_MSK 0x0010
54#define ALTERA_UART_STATUS_TMT_MSK 0x0020
55#define ALTERA_UART_STATUS_TRDY_MSK 0x0040
56#define ALTERA_UART_STATUS_RRDY_MSK 0x0080
57#define ALTERA_UART_STATUS_E_MSK 0x0100
58#define ALTERA_UART_STATUS_DCTS_MSK 0x0400
59#define ALTERA_UART_STATUS_CTS_MSK 0x0800
60#define ALTERA_UART_STATUS_EOP_MSK 0x1000
61
62
63#define ALTERA_UART_CONTROL_PE_MSK 0x0001
64#define ALTERA_UART_CONTROL_FE_MSK 0x0002
65#define ALTERA_UART_CONTROL_BRK_MSK 0x0004
66#define ALTERA_UART_CONTROL_ROE_MSK 0x0008
67#define ALTERA_UART_CONTROL_TOE_MSK 0x0010
68#define ALTERA_UART_CONTROL_TMT_MSK 0x0020
69#define ALTERA_UART_CONTROL_TRDY_MSK 0x0040
70#define ALTERA_UART_CONTROL_RRDY_MSK 0x0080
71#define ALTERA_UART_CONTROL_E_MSK 0x0100
72
73#define ALTERA_UART_CONTROL_TRBK_MSK 0x0200
74#define ALTERA_UART_CONTROL_DCTS_MSK 0x0400
75#define ALTERA_UART_CONTROL_RTS_MSK 0x0800
76#define ALTERA_UART_CONTROL_EOP_MSK 0x1000
77
78
79
80
81struct altera_uart {
82 struct uart_port port;
83 struct timer_list tmr;
84 unsigned int sigs;
85 unsigned short imr;
86};
87
88static u32 altera_uart_readl(struct uart_port *port, int reg)
89{
90 return readl(port->membase + (reg << port->regshift));
91}
92
93static void altera_uart_writel(struct uart_port *port, u32 dat, int reg)
94{
95 writel(dat, port->membase + (reg << port->regshift));
96}
97
98static unsigned int altera_uart_tx_empty(struct uart_port *port)
99{
100 return (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
101 ALTERA_UART_STATUS_TMT_MSK) ? TIOCSER_TEMT : 0;
102}
103
104static unsigned int altera_uart_get_mctrl(struct uart_port *port)
105{
106 struct altera_uart *pp = container_of(port, struct altera_uart, port);
107 unsigned int sigs;
108
109 sigs = (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
110 ALTERA_UART_STATUS_CTS_MSK) ? TIOCM_CTS : 0;
111 sigs |= (pp->sigs & TIOCM_RTS);
112
113 return sigs;
114}
115
116static void altera_uart_set_mctrl(struct uart_port *port, unsigned int sigs)
117{
118 struct altera_uart *pp = container_of(port, struct altera_uart, port);
119
120 pp->sigs = sigs;
121 if (sigs & TIOCM_RTS)
122 pp->imr |= ALTERA_UART_CONTROL_RTS_MSK;
123 else
124 pp->imr &= ~ALTERA_UART_CONTROL_RTS_MSK;
125 altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
126}
127
128static void altera_uart_start_tx(struct uart_port *port)
129{
130 struct altera_uart *pp = container_of(port, struct altera_uart, port);
131
132 pp->imr |= ALTERA_UART_CONTROL_TRDY_MSK;
133 altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
134}
135
136static void altera_uart_stop_tx(struct uart_port *port)
137{
138 struct altera_uart *pp = container_of(port, struct altera_uart, port);
139
140 pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
141 altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
142}
143
144static void altera_uart_stop_rx(struct uart_port *port)
145{
146 struct altera_uart *pp = container_of(port, struct altera_uart, port);
147
148 pp->imr &= ~ALTERA_UART_CONTROL_RRDY_MSK;
149 altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
150}
151
152static void altera_uart_break_ctl(struct uart_port *port, int break_state)
153{
154 struct altera_uart *pp = container_of(port, struct altera_uart, port);
155 unsigned long flags;
156
157 spin_lock_irqsave(&port->lock, flags);
158 if (break_state == -1)
159 pp->imr |= ALTERA_UART_CONTROL_TRBK_MSK;
160 else
161 pp->imr &= ~ALTERA_UART_CONTROL_TRBK_MSK;
162 altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
163 spin_unlock_irqrestore(&port->lock, flags);
164}
165
166static void altera_uart_set_termios(struct uart_port *port,
167 struct ktermios *termios,
168 struct ktermios *old)
169{
170 unsigned long flags;
171 unsigned int baud, baudclk;
172
173 baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
174 baudclk = port->uartclk / baud;
175
176 if (old)
177 tty_termios_copy_hw(termios, old);
178 tty_termios_encode_baud_rate(termios, baud, baud);
179
180 spin_lock_irqsave(&port->lock, flags);
181 uart_update_timeout(port, termios->c_cflag, baud);
182 altera_uart_writel(port, baudclk, ALTERA_UART_DIVISOR_REG);
183 spin_unlock_irqrestore(&port->lock, flags);
184
185
186
187
188
189
190}
191
192static void altera_uart_rx_chars(struct altera_uart *pp)
193{
194 struct uart_port *port = &pp->port;
195 unsigned char ch, flag;
196 unsigned short status;
197
198 while ((status = altera_uart_readl(port, ALTERA_UART_STATUS_REG)) &
199 ALTERA_UART_STATUS_RRDY_MSK) {
200 ch = altera_uart_readl(port, ALTERA_UART_RXDATA_REG);
201 flag = TTY_NORMAL;
202 port->icount.rx++;
203
204 if (status & ALTERA_UART_STATUS_E_MSK) {
205 altera_uart_writel(port, status,
206 ALTERA_UART_STATUS_REG);
207
208 if (status & ALTERA_UART_STATUS_BRK_MSK) {
209 port->icount.brk++;
210 if (uart_handle_break(port))
211 continue;
212 } else if (status & ALTERA_UART_STATUS_PE_MSK) {
213 port->icount.parity++;
214 } else if (status & ALTERA_UART_STATUS_ROE_MSK) {
215 port->icount.overrun++;
216 } else if (status & ALTERA_UART_STATUS_FE_MSK) {
217 port->icount.frame++;
218 }
219
220 status &= port->read_status_mask;
221
222 if (status & ALTERA_UART_STATUS_BRK_MSK)
223 flag = TTY_BREAK;
224 else if (status & ALTERA_UART_STATUS_PE_MSK)
225 flag = TTY_PARITY;
226 else if (status & ALTERA_UART_STATUS_FE_MSK)
227 flag = TTY_FRAME;
228 }
229
230 if (uart_handle_sysrq_char(port, ch))
231 continue;
232 uart_insert_char(port, status, ALTERA_UART_STATUS_ROE_MSK, ch,
233 flag);
234 }
235
236 spin_unlock(&port->lock);
237 tty_flip_buffer_push(&port->state->port);
238 spin_lock(&port->lock);
239}
240
241static void altera_uart_tx_chars(struct altera_uart *pp)
242{
243 struct uart_port *port = &pp->port;
244 struct circ_buf *xmit = &port->state->xmit;
245
246 if (port->x_char) {
247
248 altera_uart_writel(port, port->x_char, ALTERA_UART_TXDATA_REG);
249 port->x_char = 0;
250 port->icount.tx++;
251 return;
252 }
253
254 while (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
255 ALTERA_UART_STATUS_TRDY_MSK) {
256 if (xmit->head == xmit->tail)
257 break;
258 altera_uart_writel(port, xmit->buf[xmit->tail],
259 ALTERA_UART_TXDATA_REG);
260 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
261 port->icount.tx++;
262 }
263
264 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
265 uart_write_wakeup(port);
266
267 if (xmit->head == xmit->tail) {
268 pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
269 altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
270 }
271}
272
273static irqreturn_t altera_uart_interrupt(int irq, void *data)
274{
275 struct uart_port *port = data;
276 struct altera_uart *pp = container_of(port, struct altera_uart, port);
277 unsigned int isr;
278
279 isr = altera_uart_readl(port, ALTERA_UART_STATUS_REG) & pp->imr;
280
281 spin_lock(&port->lock);
282 if (isr & ALTERA_UART_STATUS_RRDY_MSK)
283 altera_uart_rx_chars(pp);
284 if (isr & ALTERA_UART_STATUS_TRDY_MSK)
285 altera_uart_tx_chars(pp);
286 spin_unlock(&port->lock);
287
288 return IRQ_RETVAL(isr);
289}
290
291static void altera_uart_timer(unsigned long data)
292{
293 struct uart_port *port = (void *)data;
294 struct altera_uart *pp = container_of(port, struct altera_uart, port);
295
296 altera_uart_interrupt(0, port);
297 mod_timer(&pp->tmr, jiffies + uart_poll_timeout(port));
298}
299
300static void altera_uart_config_port(struct uart_port *port, int flags)
301{
302 port->type = PORT_ALTERA_UART;
303
304
305 altera_uart_writel(port, 0, ALTERA_UART_CONTROL_REG);
306
307 altera_uart_writel(port, 0, ALTERA_UART_STATUS_REG);
308}
309
310static int altera_uart_startup(struct uart_port *port)
311{
312 struct altera_uart *pp = container_of(port, struct altera_uart, port);
313 unsigned long flags;
314 int ret;
315
316 if (!port->irq) {
317 setup_timer(&pp->tmr, altera_uart_timer, (unsigned long)port);
318 mod_timer(&pp->tmr, jiffies + uart_poll_timeout(port));
319 return 0;
320 }
321
322 ret = request_irq(port->irq, altera_uart_interrupt, 0,
323 DRV_NAME, port);
324 if (ret) {
325 pr_err(DRV_NAME ": unable to attach Altera UART %d "
326 "interrupt vector=%d\n", port->line, port->irq);
327 return ret;
328 }
329
330 spin_lock_irqsave(&port->lock, flags);
331
332
333 pp->imr = ALTERA_UART_CONTROL_RRDY_MSK;
334 writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
335
336 spin_unlock_irqrestore(&port->lock, flags);
337
338 return 0;
339}
340
341static void altera_uart_shutdown(struct uart_port *port)
342{
343 struct altera_uart *pp = container_of(port, struct altera_uart, port);
344 unsigned long flags;
345
346 spin_lock_irqsave(&port->lock, flags);
347
348
349 pp->imr = 0;
350 writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
351
352 spin_unlock_irqrestore(&port->lock, flags);
353
354 if (port->irq)
355 free_irq(port->irq, port);
356 else
357 del_timer_sync(&pp->tmr);
358}
359
360static const char *altera_uart_type(struct uart_port *port)
361{
362 return (port->type == PORT_ALTERA_UART) ? "Altera UART" : NULL;
363}
364
365static int altera_uart_request_port(struct uart_port *port)
366{
367
368 return 0;
369}
370
371static void altera_uart_release_port(struct uart_port *port)
372{
373
374}
375
376static int altera_uart_verify_port(struct uart_port *port,
377 struct serial_struct *ser)
378{
379 if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_ALTERA_UART))
380 return -EINVAL;
381 return 0;
382}
383
384#ifdef CONFIG_CONSOLE_POLL
385static int altera_uart_poll_get_char(struct uart_port *port)
386{
387 while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
388 ALTERA_UART_STATUS_RRDY_MSK))
389 cpu_relax();
390
391 return altera_uart_readl(port, ALTERA_UART_RXDATA_REG);
392}
393
394static void altera_uart_poll_put_char(struct uart_port *port, unsigned char c)
395{
396 while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
397 ALTERA_UART_STATUS_TRDY_MSK))
398 cpu_relax();
399
400 altera_uart_writel(port, c, ALTERA_UART_TXDATA_REG);
401}
402#endif
403
404
405
406
407static struct uart_ops altera_uart_ops = {
408 .tx_empty = altera_uart_tx_empty,
409 .get_mctrl = altera_uart_get_mctrl,
410 .set_mctrl = altera_uart_set_mctrl,
411 .start_tx = altera_uart_start_tx,
412 .stop_tx = altera_uart_stop_tx,
413 .stop_rx = altera_uart_stop_rx,
414 .break_ctl = altera_uart_break_ctl,
415 .startup = altera_uart_startup,
416 .shutdown = altera_uart_shutdown,
417 .set_termios = altera_uart_set_termios,
418 .type = altera_uart_type,
419 .request_port = altera_uart_request_port,
420 .release_port = altera_uart_release_port,
421 .config_port = altera_uart_config_port,
422 .verify_port = altera_uart_verify_port,
423#ifdef CONFIG_CONSOLE_POLL
424 .poll_get_char = altera_uart_poll_get_char,
425 .poll_put_char = altera_uart_poll_put_char,
426#endif
427};
428
429static struct altera_uart altera_uart_ports[CONFIG_SERIAL_ALTERA_UART_MAXPORTS];
430
431#if defined(CONFIG_SERIAL_ALTERA_UART_CONSOLE)
432
433static void altera_uart_console_putc(struct uart_port *port, int c)
434{
435 while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
436 ALTERA_UART_STATUS_TRDY_MSK))
437 cpu_relax();
438
439 writel(c, port->membase + ALTERA_UART_TXDATA_REG);
440}
441
442static void altera_uart_console_write(struct console *co, const char *s,
443 unsigned int count)
444{
445 struct uart_port *port = &(altera_uart_ports + co->index)->port;
446
447 uart_console_write(port, s, count, altera_uart_console_putc);
448}
449
450static int __init altera_uart_console_setup(struct console *co, char *options)
451{
452 struct uart_port *port;
453 int baud = CONFIG_SERIAL_ALTERA_UART_BAUDRATE;
454 int bits = 8;
455 int parity = 'n';
456 int flow = 'n';
457
458 if (co->index < 0 || co->index >= CONFIG_SERIAL_ALTERA_UART_MAXPORTS)
459 return -EINVAL;
460 port = &altera_uart_ports[co->index].port;
461 if (!port->membase)
462 return -ENODEV;
463
464 if (options)
465 uart_parse_options(options, &baud, &parity, &bits, &flow);
466
467 return uart_set_options(port, co, baud, parity, bits, flow);
468}
469
470static struct uart_driver altera_uart_driver;
471
472static struct console altera_uart_console = {
473 .name = "ttyAL",
474 .write = altera_uart_console_write,
475 .device = uart_console_device,
476 .setup = altera_uart_console_setup,
477 .flags = CON_PRINTBUFFER,
478 .index = -1,
479 .data = &altera_uart_driver,
480};
481
482static int __init altera_uart_console_init(void)
483{
484 register_console(&altera_uart_console);
485 return 0;
486}
487
488console_initcall(altera_uart_console_init);
489
490#define ALTERA_UART_CONSOLE (&altera_uart_console)
491
492#else
493
494#define ALTERA_UART_CONSOLE NULL
495
496#endif
497
498
499
500
501static struct uart_driver altera_uart_driver = {
502 .owner = THIS_MODULE,
503 .driver_name = DRV_NAME,
504 .dev_name = "ttyAL",
505 .major = SERIAL_ALTERA_MAJOR,
506 .minor = SERIAL_ALTERA_MINOR,
507 .nr = CONFIG_SERIAL_ALTERA_UART_MAXPORTS,
508 .cons = ALTERA_UART_CONSOLE,
509};
510
511#ifdef CONFIG_OF
512static int altera_uart_get_of_uartclk(struct platform_device *pdev,
513 struct uart_port *port)
514{
515 int len;
516 const __be32 *clk;
517
518 clk = of_get_property(pdev->dev.of_node, "clock-frequency", &len);
519 if (!clk || len < sizeof(__be32))
520 return -ENODEV;
521
522 port->uartclk = be32_to_cpup(clk);
523
524 return 0;
525}
526#else
527static int altera_uart_get_of_uartclk(struct platform_device *pdev,
528 struct uart_port *port)
529{
530 return -ENODEV;
531}
532#endif
533
534static int altera_uart_probe(struct platform_device *pdev)
535{
536 struct altera_uart_platform_uart *platp = dev_get_platdata(&pdev->dev);
537 struct uart_port *port;
538 struct resource *res_mem;
539 struct resource *res_irq;
540 int i = pdev->id;
541 int ret;
542
543
544 if (i == -1) {
545 for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS; i++)
546 if (altera_uart_ports[i].port.mapbase == 0)
547 break;
548 }
549
550 if (i < 0 || i >= CONFIG_SERIAL_ALTERA_UART_MAXPORTS)
551 return -EINVAL;
552
553 port = &altera_uart_ports[i].port;
554
555 res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
556 if (res_mem)
557 port->mapbase = res_mem->start;
558 else if (platp)
559 port->mapbase = platp->mapbase;
560 else
561 return -EINVAL;
562
563 res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
564 if (res_irq)
565 port->irq = res_irq->start;
566 else if (platp)
567 port->irq = platp->irq;
568
569
570 if (platp)
571 port->uartclk = platp->uartclk;
572 else {
573 ret = altera_uart_get_of_uartclk(pdev, port);
574 if (ret)
575 return ret;
576 }
577
578 port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
579 if (!port->membase)
580 return -ENOMEM;
581
582 if (platp)
583 port->regshift = platp->bus_shift;
584 else
585 port->regshift = 0;
586
587 port->line = i;
588 port->type = PORT_ALTERA_UART;
589 port->iotype = SERIAL_IO_MEM;
590 port->ops = &altera_uart_ops;
591 port->flags = UPF_BOOT_AUTOCONF;
592 port->dev = &pdev->dev;
593
594 platform_set_drvdata(pdev, port);
595
596 uart_add_one_port(&altera_uart_driver, port);
597
598 return 0;
599}
600
601static int altera_uart_remove(struct platform_device *pdev)
602{
603 struct uart_port *port = platform_get_drvdata(pdev);
604
605 if (port) {
606 uart_remove_one_port(&altera_uart_driver, port);
607 port->mapbase = 0;
608 }
609
610 return 0;
611}
612
613#ifdef CONFIG_OF
614static const struct of_device_id altera_uart_match[] = {
615 { .compatible = "ALTR,uart-1.0", },
616 { .compatible = "altr,uart-1.0", },
617 {},
618};
619MODULE_DEVICE_TABLE(of, altera_uart_match);
620#endif
621
622static struct platform_driver altera_uart_platform_driver = {
623 .probe = altera_uart_probe,
624 .remove = altera_uart_remove,
625 .driver = {
626 .name = DRV_NAME,
627 .of_match_table = of_match_ptr(altera_uart_match),
628 },
629};
630
631static int __init altera_uart_init(void)
632{
633 int rc;
634
635 rc = uart_register_driver(&altera_uart_driver);
636 if (rc)
637 return rc;
638 rc = platform_driver_register(&altera_uart_platform_driver);
639 if (rc)
640 uart_unregister_driver(&altera_uart_driver);
641 return rc;
642}
643
644static void __exit altera_uart_exit(void)
645{
646 platform_driver_unregister(&altera_uart_platform_driver);
647 uart_unregister_driver(&altera_uart_driver);
648}
649
650module_init(altera_uart_init);
651module_exit(altera_uart_exit);
652
653MODULE_DESCRIPTION("Altera UART driver");
654MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
655MODULE_LICENSE("GPL");
656MODULE_ALIAS("platform:" DRV_NAME);
657MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_ALTERA_MAJOR);
658